Posted
by
ScuttleMonkeyon Friday January 08, 2010 @06:13PM
from the better-golems-on-the-way dept.

Bob the Super Hamster writes "The BBC is reporting that scientists in Italy have developed a method to convert rattan wood into a bone-like substance. The bone replacement is currently being tested in sheep, where, when inserted into the area of a fracture, it joins with the existing bone and eventually fuses. Unlike other bone replacements, this one actually has load-bearing ability and also naturally fuses with the existing bone. Additionally, since it is porous like real bone, nerves and blood vessels can pass through it."

the only thing they could do make an opposing force, is to find a way to let nerves and blood cells pass through a porous metal... we'll call it adamantium. And we can then infuse and re build limbs out of this nearly indestructible metal... The only enemy of these sure humans: Airports.

When an artificial hip, or other load-bearing bone implant, has a higher modulus than bone (and they invariably do), they cause the load to be transmitted unevenly to the bone. The artificial hip is on a pin that goes down into the marrow on the top of the femur. In natural loading, each segment of bone (taken from top to bottom) is loaded equally in compression. With an artificial hip implanted, some of the force is transmitted directly to a deeper part of the femur. The top of the bone is loaded less heavily than it would have been under natural circumstances.

There. I've just become automatically plus five insightful, thanks to this guy [slashdot.org]. Free karma, THAT is how you do it.

.....Informative mod.....you actually managed to talk about your penis on the internet and have it modded informative. Wow. This kind of thing is going to be what makes up stories for our grandchildren when we get older.

Now, I'm not entirely up on my E&M, but this ought to be somewhat informative to some people reading it. There are only three metallic elements (not including Rare Earth Metals) that can be magnetized: Iron, Nickel, and Cobalt. Titanium is not one of them, thus it won't be sucked toward a simple magnet. Note: Steel has Iron in it, that's why it is attracted to magnets and can be magnetized, etc...

Therefore, the reason why everyone uses titanium implants may be because they CAN in fact be near (or in)

If the conductor follows a path that keeps the strength of the magnetic field constant, there will be no induced electric current. Without knowing much about MRI machines (specifically the shape of their field), I can't say whether it's likely or not to move along such a path. If the conductor moves such that the strength of the magnetic field at the conductor barely changes, there would be barely any current induced.

One case where no current would be produced would be if a conductor is moved parallel to

If the conductor follows a path that keeps the strength of the magnetic field constant, there will be no induced electric current.

Actually, there will be. Any charge moving in a magnetic field, whether that field is constant or not, will experience a force perpendicular to the velocity and the magnetic field. I understand where you might get this idea, because on the surface it makes sense -- if the field is constant, how could an electron "know" that it is moving vs. stationary, since the field doesn't c

You hit the key point yourself. An MRI has a huge, static magnetic field. But it also bombards the target with radio frequency radiation. Normally, the RF would simply cause the nuclei (and atoms they are a part of) to vibrate, but because of the large static field, their spin is contrained and instead the nuclei PRECESS, like a gyroscope tipped off axis will precess around the point of support without falling -- and as they do so, they give off radiation which can be detected. It is not the static magnetic

Very interesting, I don't know anything about that yet. What does such an effect depend upon? It obviously depends on the material and its metallic properties. Does it depend on the quantity of the material? Why does it apply only to metals? Would it apply to metals that do not conduct well, like Tungsten? Is your post theory, or is the effect known to be significant enough to be serious? Do you have any theories about why we are not using plastics instead of titanium then?

I looked a few things up and was surprised to find that smaller, non-ferromagnetic metal objects can be safely scanned. The thing that is disputed is whether the presence of metal interferes too much with the received image. Metal will absorb some RF but reflect a great deal more, and the RF energy bouncing around could potentially ruin the image, or bounce back into the resonant cavity and even destroy it.

I don't think anybody would ever put somebody with a LARGE metal implant, like a femur, into an MRI th

Note: I am a physician who majored in chemistry, but not a radiologist. Some of what is to follow is based on NMR, not specifically on MRI. I have, where possible, backed up my instincts with the Wikipedia article. I have made every effort not to say something incorrect, but I am human.

An MRI has its magnets arranged to produce a solenoid effect - a constant magnetic field of extraordinary strength. This flows in one direction through the bore of the magnet, producing a linear magnetic field. In this

As a welder and metalsmith with a background in bike racing that left me with several metal-containing surgical repairs, I'm already completely hosed with respect to MRI's, so bring on the titanium bone replacements, say I!

A friend of mine used to do IT support for a company that made NMR's. They were *very* early adopters of LCD screens because CRT's were so hideously distorted even rooms away from the machines. They had security guards whose sole job it was to pat people down if they were going to be e